<!DOCTYPE html>
<html lang="en">
<head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <meta http-equiv="X-UA-Compatible" content="ie=edge">
     <title>socket.demo</title>
     <script src='http://localhost:8081/socket.io/socket.io.js'></script>
     <script>
          let socket = io.connect('ws://localhost:8081/')
          socket.emit('a', 12, 3, 4, 5)
     </script>
</head>
<body>

</body>
</html>
